Lesson: Punnet Squares

How do we predict the outcomes of crosses based on Mendel's Laws?

This lesson develops the students' abilities to predict the potential results of genetic crosses. They will use their knowledge of vocabulary and the rules set down in the use of Punnet Squares

#content #criticalthinking #community #collaboration #communication #creativity

Objectives and Vocabulary: #content

BIO.5 The student will investigate and understand common mechanisms of inheritance and protein synthesis. Key concepts include

d) prediction of inheritance of traits based on the Mendelian laws of heredity;

f) genetic variation;

    • Genetically diverse populations are more likely to survive changing environments. Recombination and mutation provide for genetic diversity. Some new gene combinations have little effect, some can produce organisms that are better suited to their environments, and others can be deleterious.

    • Use a Punnett square to show all possible combinations of gametes and the likelihood that particular combinations will occur in monohybrid and dihybrid crosses.

Vocabulary

Mendelian laws

Heredity

Genetic Variation

Recombination

Mutation

Genetic Diversity

Deleterious

Punnet Square

Probability

Prediction

Genetic Cross


Monohybrid cross

Dihybrid cross

Genotype

Phenotype

Homozygous

Heterozygous

Allele

Dominant

Recessive

Warm Ups, etc:

Punnett Square Review - students review and practice performing crosses and predicting outcomes

1 Trait, 2 Trait - students practice performing mono- and dihybrid crosses

Test Cross - students perform crosses and discuss why one would use the "pure-bred homozygous recessive" phenotype in performing a test cross.

Alleles and Independent Assortment - formative assessment for determining how alleles segregate and how the Law of Independent Assortment is applied in dihybrid crosses.

Lecture Notes: #content

Notes - Punnett Squares - information about Mendel and his peas and the terms and rules for predicting probability outcomes of monohybrid crosses.

Notes - Dihybrid Crosses - information about test crossing and how the Law of Independent Assortment is applied in predicting crosses involving two traits

Activities, Assignments, Etc.

Ted-ED: Mendel's Peas- https://www.youtube.com/watch?v=Mehz7tCxjSE

Crash Course Biology- Ear Wax- https://www.youtube.com/watch?v=CBezq1fFUEA

Independent Practice (Critical Thinking WS 8-1/Rabbits)

continue to Non-Mendellian lesson